The objectives of this research are to compare the fine structure and modulation of synthesis of proteoglycans in normal cartilage, human benign and malignant cartilaginous tumors, and a model system--the Swarm rat chondrosarcoma. There will be an emphasis on the differences between aggregating and nonaggregating proteoglycans, the proteoglycan link-protein relationship, and the occurrence of keratan sulfate or "keratan sulfate-like" glycopeptides. The methods will involve chemical characterization of isolated proteoglycan fractions and analysis of isotopically labeled materials from cultured cells. Proteoglycans will be extracted from the tissue with guanidinium chloride in the presence of protease inhibitors and purified in cesium chloride gradients under associative conditions. The aggregating and nonaggregating fractions will be separated by Sepharose 2B column chromatography and the aggregated fraction further fractionated by buoyant density in a dissociative cesium chloride gradient. The resulting fractions will be assayed physically, biochemically, and immunologically. Selected fractions will be degraded (either chemically or enzymatically), fractionated, and reassayed. Cells will be grown by standard techniques, pulsed with precursors (H3-GlcN and C14-serine), and the labeled products analyzed to determine the rate of synthesis and nature of the products produced. Culture cells will be used to evaluate the effect of increasing passage number, the addition of materials such as somatomedin or hyaluronic acid, and the addition of proteoglycans and/or collagen to the media. The noncollagen, nonproteoglycan matrix molecules will also be examined electrophoretically and detected either chemically or by autoradiography. The tissue will be evaluated by standard histochemical procedures. In addition, lectin-binding profiles will be obtained using a light level peroxidase-coupled procedure to determine if a differentiation between benign and low-grade malignant tumors can be made by this procedure.